CN1693441B - Continuously variable transmission fluid - Google Patents

Abstract

A composition suitable for lubricating a continuously variable transmission comprising a lubricating oil containing an ashless dispersant, a spiro bicyclodiphosphite, a calcium detergent lubricating oil additive, and, optionally, a succinimide friction modifier and an organic mono- or di-hydrogen phosphite.

Description

Continuously variable transmission fluid

technical field

The present invention relates to compositions and methods for lubricating continuously variable transmission (CVT) driven steel belts or chains. More particularly, the present invention relates to spirobicyclic diphosphite-containing lubricating compositions useful as continuously variable transmission fluids that exhibit enhanced steel-to-steel friction compared to conventional fluids.

Background technique

Continued research into more fuel-efficient vehicles has led to the development of continuously variable transmissions by several manufacturers. The main difference between a CVT and a regular automatic transmission is that an automatic transmission uses planetary gear sets to accomplish speed changes, while a CVT uses pulleys and a belt or chain to change speed. Conventional automatic transmissions typically have 3, 4 or 5 fixed reduction ratios or "speeds", such as a 5-speed automatic transmission. The transmission's operating system selects the appropriate reduction ratio or speed based on engine rpm, ground speed and throttle position. In a CVT, by varying the relative radii of the drive belt or chain motion on the drive or driven pulleys, within fixed limits, an almost infinite variety of reduction ratios can be obtained.

The key device in a CVT is the transmission. The variator consists of two steel pulleys and a steel belt or chain. Pulleys can be open and closed, allowing the belt or chain to move at different radii. When the drive pulley is fully open (small radius of belt movement) and the driven pulley is fully closed (large radius of belt movement), a very high reduction ratio (resulting in low ground speed) is obtained. Conversely, when the drive pulley is fully closed (large radius of belt motion) and the driven pulley is fully open (small radius of belt motion), an increase in output speed relative to input speed is obtained (resulting in high ground speed).

The novelty of this design is that the belt is made of steel. There are two types of CVT devices. In one design, a steel belt is used and "pushed" or compressed to transmit power, while in another design power is transmitted by steel connecting chains that are pulled, as is the case with more common V-belts. Since power is transmitted in both designs using steel elements in contact with steel pulleys, the need for lubrication is the same for both designs.

The most critical requirement for a lubricant for a CVT transmission is that the lubricant should provide a high level of steel-to-steel friction. Since the steel-to-steel coefficient of friction of common lubricants tends to be very low, very high closing forces need to be applied to the sheave sides to avoid slippage of the belt if these lubricants are used. Any slippage of the belt will cause severe wear which will quickly lead to failure. The pulleys are manufactured to the utmost precision and have precise surface finishing to allow optimum operation. There must not be any wear on these surfaces. Therefore, a suitable lubricant must provide the highest possible coefficient of friction at the steel-steel interface.

Since the purpose of using CVTs is to produce vehicles with improved fuel efficiency, they can often be equipped with torque converters with slip clutch systems. The fuel efficiency gains possible when using slipping torque converter clutches are well known. Stick-slip behavior, when not avoided by the lubricant, manifests itself in the form of vibrations in slipping torque converter clutches. Therefore, these lubricants must still have excellent paper-to-steel friction properties.

To successfully avoid stick-slip behavior in slipping torque converter clutches, the lubricant must have excellent friction control at low slip speeds. More specifically, lubricants must provide a stick-slip friction-free environment at low sliding speeds. This frictional property is determined by calculating the friction-velocity relationship or dμ/dV [variation of coefficient of friction (μ) with velocity (V)] for a system defined by the lubricant and friction substances used. In order to successfully control stick-slip behavior, this relationship, dμ/dV, must always be positive, i.e., the coefficient of friction must always increase with increasing sliding velocity. Also, the more positive dμ/dV, the greater the margin of safety provided by the lubricant with respect to stick-slip behavior.

Attempts have been made in the past to formulate continuously variable transmission fluids that provide the proper amount of lubrication while allowing sufficient friction between the belt and the pulleys to avoid slippage of the belt during high torque transfer from the engine. One such lubricant is disclosed in WO 98/39400, published November 1998, which describes compositions comprising a mixture of: (1) a major amount of lubricating oil; and (2) an effective amount of a combination of performance enhancing additives , comprising (a) an ashless dispersant, (b) a metal cleaner, (c) an organophosphite, (d) an amine salt of an organophosphate, and (e) one or more friction modifiers , such as amide friction modifiers, succinimide friction modifiers and ethoxylated amine friction modifiers. See US-A-5,750,477 (Sumiejski et al.), published May 12, 1998 and incorporated herein by reference. However, these lubricants do not address the dμ/dV control problem.

US Patent 4832867 (1989) discloses the use of spirobicyclic phosphites in lubricating oils, but always needs to be used in combination with organomolybdenum compounds. The fluids of the present invention are free of molybdenum. Compounds of molybdenum, such as molybdenum disulfide, molybdenum thiocarbamate and molybdenum carboxylate, are well known friction reducing agents. They are widely used in gear applications and in automotive crankcases to improve the energy efficiency of those devices. The aim of the present invention is to increase steel-steel friction, so molybdenum complexes must be excluded from these compositions.

We have discovered a unique combination of additives and friction modifiers that addresses the lubrication difficulties created by steel-steel pulley systems and slipping torque converter clutches in continuously variable transmissions. In particular, the present inventors have discovered that certain spirobicyclic diphosphites can provide continuously variable transmission fluids that exhibit significantly improved steel-to-steel friction properties. While these CVT fluids also contain certain imide friction modifiers, they are particularly suitable for use in CVTs including slipping torque converter clutches.

Summary of the invention

The present invention relates to a composition and method for lubricating a continuously variable transmission comprising:

(1) a major quantity of lubricating oil; and

(2) An effective amount of a performance enhancing additive combination comprising

(a) Ashless dispersants;

(b) an effective amount of spirobicyclic diphosphite of formula I,

Formula I

wherein R and _R can be the same or different aliphatic hydrocarbon groups, preferably an alkyl or alkenyl group with about 1-30 carbons, more preferably an alkyl or alkenyl group with 4-16 carbons, most preferably a _C10 alkyl group . Alkyl or alkenyl groups may contain ring structures or heteroatoms;

(c) calcium lubricating oil detergent additive;

(d) an optional succinimide friction modifier of formula II, and wherein R ₂ and R ₃ may be the same or different and are C ₆ -C ₃₀ alkyl, and z=1-10;

Formula II

(e) an optional organic phosphite of formula III,

Formula III

wherein _R4 is hydrocarbyl and _R5 is hydrocarbyl or hydrogen with the proviso that the composition is free of molybdenum.

Another embodiment of the invention is a continuously variable transmission comprising the fluid of the invention.

Detailed description of the invention

Lubrication of a CVT transmission with a steel-steel friction transmission and slip torque converter clutch system is not a simple matter. Providing high steel-to-steel friction for transmissions and good paper-to-steel friction for torque converter clutches presents a special problem. The development of a high steel-to-steel friction for transmissions can be achieved through the use of the spirobicyclic diphosphite and calcium detergents of the present invention. Spirobicyclic diphosphites can also improve the properties of fluids containing simple organic diphosphites. Certain succinamide-based friction modifiers are compatible with the present system and impart the excellent paper-to-steel friction characteristics of the products of the present invention.

1. Lubricating oil

Lubricating oils useful in the present invention are those derived from natural lubricating oils, synthetic lubricating oils and mixtures thereof. Usually natural and synthetic lubricating oils have dynamic viscosities ranging from about 1 to about 100 mm ² /s (cSt) at 100°C, while typical applications require lubricating oils or lubricating oil mixtures with viscosities at 100°C ranging from About 2 to about 8 mm ² /s (cSt).

Natural lubricating oils include animal oils, vegetable oils (such as castor oil and lard), petroleum, mineral oils, and oils derived from coal or shale. A preferred natural lubricating oil is mineral oil.

Suitable mineral oils include all common mineral oil bases. This includes oils whose chemical structure is cycloalkyl or olefin based. Oils can be refined by conventional methods using acids, alkalis and clays or other agents such as aluminum chloride, or they can be produced by solvent extraction with solvents such as phenol, sulfur dioxide, furfural, dichlorodiethyl ether, etc. Extract oil. They can be hydrotreated or hydrofinished, dewaxed by freezing or catalytic dewaxing, or hydrocracked. Mineral oils may be produced from natural sources or consist of isomerized waxy substances or residues of other refining processes.

Typical mineral oils have dynamic viscosities ranging from 2.0mm ² /s (cSt) to 8.0mm ² /s (cSt) at 100°C. Preferred mineral oils have a kinematic viscosity of from 2 to 6 mm ² /s (cSt), most preferred mineral oils are those having a kinematic viscosity at 100°C of 3 to 5 mm ² /s (cSt).

Synthetic lubricating oils include hydrocarbon oils and halogen-substituted hydrocarbon oils such as oligomeric, polymeric or interpolyolefins [e.g. polybutene, polypropylene, propylene, isobutylene copolymers, chlorinated polylactene, poly(1-hexene), poly( 1-octene), poly(1-decene), etc., and mixtures thereof]; alkylbenzenes [such as dodecylbenzene, tetradecylbenzene, dinonylbenzene, di(2-ethylhexyl)benzene etc.]; polyphenylene [such as biphenyl, terphenyl, alkylated polyphenylene, etc.]; Among such synthetic oils, preferred oils are oligomers of alpha-olefins, especially oligomers of 1-decene.

Synthetic lubricating oils also include polymers, interpolymers, copolymers, and derivatives of alkylene oxides where the terminal hydroxyl groups have been modified by esterification, etherification, or the like. Examples of such synthetic oils are polyalkylene oxide polymers prepared by the polymerization of ethylene oxide or propylene oxide; alkyl ethers or aryl ethers of these polyalkylene oxide polymers (e.g. with an average molecular weight of 1000 methyl-polyisopropylene glycol ether, polypropylene glycol diphenyl ether with a molecular weight of 1000 to 1500); and monobasic or dibasic carboxylate (such as acetate, mixed C ₃ - C ₈ fatty acid esters, and C ₁₂ oxyacid diesters of tetraethylene glycol).

Another class of suitable synthetic lubricating oils contains dicarboxylic acids (such as phthalic, succinic, alkyl and alkenyl succinic acids, maleic, azelaic, suberic, sebacic, fumaric, acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acid, allylmalonic acid, etc.) and various alcohols (such as butanol, hexanol, dodecanol, 2- Ethyl hexanol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.) obtained esters. Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, azelaic acid, diisodecyl phthalate, dioctyl phthalate, didecyl phthalate, bis(eicosyl) sebacate, bis(2-ethylhexyl) linoleic acid dimer, and mixed esters obtained by reacting 1 mol of sebacic acid (sebasic acid), 2 mol of tetraethylene glycol, and 2 mol of 2-ethyl-hexanoic acid, and the like. Preferred synthetic oils of this type are adipates of _C4 to _C12 alcohols.

Esters used as synthetic lubricating oils also include those obtained from C ₅ to C ₁₂ monocarboxylic acids and polyhydroxy compounds and polyhydroxy ethers such as neopentyl glycol, trimethylol propane pentaerythritol, dipentaerythritol, tripentaerythritol, etc. kind.

Silicon-based oils such as polyalkyl, polyaryl, polyalkoxy or polyaryloxysilane and silicate oils constitute another class of useful synthetic lubricating oils. These oils include tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl) silicate, tetra -(p-tert-butylphenyl)ester, hexa-(4-methyl-2-pentyloxy)-disiloxane, poly(methyl)siloxane and poly(methylphenyl)siloxane wait. Other synthetic lubricating oils include phosphoric acid-containing liquid esters (such as tricresyl phosphate, trioctyl phosphate, diethyl decyl phosphonate), tetrahydrofuran polymers, polyalphaolefins, and the like.

Lubricating oils can also be derived from refined oils, re-refined oils or mixtures thereof. Unrefined oils may be obtained directly from natural or synthetic sources such as coal, shale or tar sands bitumen without further purification or treatment. Examples of unrefined oils include shale oils obtained directly from retorting operations, petroleum oils obtained directly from distillation, or ester oils obtained directly from esterification processes, each of which can be obtained directly without further treatment. use. Refined oils are similar to unrefined oils, except that refined oils have been treated in one or more purification steps to improve one or more properties. Suitable purification steps include distillation, hydrotreating, dewaxing, solvent extraction, acid or base extraction, filtration and percolation, all of which are known to those skilled in the art. Rerefined oils are obtained by treating used oils in a process similar to that used to obtain refined oils. These re-refined oils, also known as reclaimed or reprocessed oils, typically require additional technical treatment to remove spent additives and oil degradation products.

When the lubricating oil is a mixture of natural and synthetic lubricating oils (that is, partially synthetic), the choice of partially synthetic oil components can be very wide, but especially useful combinations are made of mineral oil and polyalphaolefin. (PAO), especially oligomers of 1-decene.

2. Additive composition

a. Ashless dispersant

Lubricants are combined with additive formulations. One component of the additive system of the present invention is an ashless dispersant. Dispersants suitable for use in the present invention include hydrocarbyl succinimides, hydrocarbyl succinamides, mixed esters/amides of hydrocarbyl-substituted succinic acids, hydroxyesters of hydrocarbyl-substituted succinic acids and hydrocarbyl-substituted phenols, Manny of formaldehyde and polyamines. Greek polycondensation products. Also useful are polycondensation products of polyamines and phenyl-substituted carboxylic acids. Mixtures of these dispersants may also be used.

Basic nitrogen-containing ashless dispersants are well known lubricating oil additives and their preparation is extensively described in the patent literature. For example, hydrocarbyl-substituted succinimides and succinamides and methods for their preparation are described, for example, in US Pat. Mixed ester-amides of hydrocarbyl substituted succinic acids are described, for example, in US Pat. Mannich dispersants, polycondensation products of hydrocarbyl-substituted phenols, formaldehyde and polyamines, are described, for example, in US Patent Nos. Amine dispersants and their preparation from high molecular weight aliphatic or cycloaliphatic halides and amines are described, for example, in US Pat.

Preferred dispersants are alkenyl succinimides and succinamides. Succinimide or succinamide dispersants can be prepared from amines containing a basic nitrogen and additionally containing one or more hydroxyl groups. Typically the amines are polyamines such as polyalkylene polyamines, hydroxyl-substituted polyamines and polyoxyalkylene polyamines. Examples of polyalkylene polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine. Low-cost poly(ethyleneamine) containing an average of about 5 to 7 nitrogen atoms per mol is commercially available under trade names such as "Polyamine H", "Polyamine 400", "Dow Polyamine E-100" etc. ) (PAM). Hydroxy substituted amines include N-hydroxyalkyl-alkylene polyamines such as N-(2-hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)piperazine and the amines described in US4873009 N-hydroxyalkylated alkylenediamines. Typical polyoxyalkylene polyamines include polyoxyethylene diamines and polyoxypropylene diamines and triamines having an average molecular weight in the range of 200 to 2500. Such products are available under the trade name Jeffamine.

Amines are readily reacted with selected hydrocarbyl-substituted dicarboxylic acid species such as alkenyl succinic anhydride by heating an oil solution containing 5 to 95% by weight of the aforementioned hydrocarbyl-substituted dicarboxylic acid species at about 100 to 250°C, preferably at 125 to 175 The reaction is carried out by heating at 1°C for 1 to 10 hours, for example 2 to 6 hours, until the required amount of water is removed. Heating is preferred to promote the formation of imides or mixtures of imides and amides rather than amides and salts. The ratio of the reaction of the hydrocarbyl-substituted dicarboxylic acid species with an equivalent of the amine and the additional nucleophilic reactants described herein can vary widely, depending on the reactants and the type of linkage formed. Typically from 0.1 to 1.0, preferably from about 0.2 to 0.6, eg 0.4 to 0.6 equivalents of dicarboxylic acid units (eg substituted succinic anhydride) are used per equivalent of reactive nucleophilic reactant (eg amine). For example, it is preferred to use about 0.8 mol of pentylamine (having two primary amine groups and 5 equivalents of reactive nitrogen per molecule) for conversion to a mixture of amides and imides, a compound obtained from the reaction of polyolefins with maleic anhydride. A composition having a functionality of 1.6; that is, it is preferred to use sufficient pentylamine to provide about 0.4 equivalents (ie, 1.6 divided by (0.8*5) equivalents) of succinic anhydride units per equivalent of amine of reactive nitrogen.

The use of alkenyl succinimides that have been treated with boronating agents is also suitable for use in the compositions of the present invention because they seal against elastomers made from materials such as fluoroelastomers and silicon-containing elastomers. components are better compatible. Dispersants can be post-treated with a number of agents known to those skilled in the art (see, eg, US Patents 3,254,025, 3,502,677, and 4,857,214).

A preferred ashless dispersant is polyisobutenyl succinimide, which is derived from polyisobutenyl succinic anhydride and an alkylene polyamine such as triethylenetetramine or tetraethylenepentamine, wherein poly The isobutyl substituents are obtained from polyisobutenes having a number average molecular weight of from 700 to 1200, preferably from 900 to 1000. It has been found that certain selections of dispersants within the range of alkenyl succinimides can improve the frictional properties of the fluid. The most preferred dispersants in the present invention are those in which the polyisobutylene substituent has a molecular weight of about 950 atomic mass, the basic nitrogen-containing group is a polyamine (PAM) and post-treated with a boronating agent.

The ashless dispersants of the present invention can be used in effective amounts. However, they are used in an amount of from about 0.1 to 10.0 mass%, preferably from about 0.5 to 7.0% and most preferably from about 2.0 to about 5.0% by mass of the final lubricant.

b. Spirobicyclic diphosphite

The key ingredient to obtain high steel-steel friction is a spirobicyclic diphosphite of formula I, wherein the R group is a C ₁ to C ₃₀ aliphatic hydrocarbon group, preferably an alkyl group, and C ₁ -C ₃₀ refers to a group having 1 to 30 carbon atoms. The alkyl group can be straight chain or branched, it can contain cyclic structures or heterocyclic atoms such as N, S, O or halogens.

Formula I

Bicyclic phosphites of this type can be prepared by reacting a tetrahydroxy compound such as pentaerythritol with an organic phosphite such as trimethyl phosphite. Such products are available commercially as Weston 600 phosphite from GE Specialty Chemical Company or Doverphos 1220 from Dover Chemical Company.

A preferred spirobicyclic diphosphite is pentaerythritol diphosphite substituted with branched alkyl groups having 3 to 18 carbon atoms. Most preferred are those in which the alkyl groups are all isodecyl (C ₁₀ ).

Spirobicyclic diphosphites can be used in effective amounts. However, in lubricating oils, they are generally used in amounts from about 0.1% to 10% by weight, preferably from 0.2% to about 8%, and the most preferred concentration is 100 to 1000 parts per million by weight of the lubricating oil. phosphorus.

c. Calcium cleaner

The compositions of the present invention calcium-containing cleansers are exemplified by oil-soluble neutral or overbased calcium salts of one or more of the following acidic substances (or mixtures thereof): (1) sulfonic acids, (2) carboxylic acids, (3) salicylic acid, (4) alkylphenol and (5) sulfurized alkylphenol.

Metal-containing oil-soluble neutral detergents are those detergents that contain an equivalent stoichiometric amount of metal compared to the amount of acidic groups present in the detergent. Therefore, typical neutral cleaners will be weakly alkaline compared to their overbased counterparts. Acidic materials used to form such cleaners include carboxylic acids, salicylic acid, alkylphenols, sulfonic acids, sulfurized alkylphenols, and the like.

The term "overbased" in connection with metal cleaners is often used to refer to metal salts in which the metal is present in a greater stoichiometry than the organic groups. The method commonly used to prepare overbased salts involves mixing a solution of the acid in mineral oil with a stoichiometric excess of a metal neutralizing agent such as metal oxides, hydroxides, carbonates, bicarbonates and sulfides at a temperature of about 50°C Heated under, and the reaction product was filtered. The use of "promoters" to help bind large excess metals during the neutralization step is also known. Examples of compounds that can be used as accelerators include phenolic substances such as phenol, naphthol, alkylphenols, thiophenols, sulfurized alkylphenols, and condensation products of formaldehyde and phenolic substances; alcohols such as methanol, 2-propane alcohols, octanol, cellosolve alcohol, carbitol, ethylene glycol, stearyl alcohol, and cyclohexanol; and amines such as aniline, phenylenediamine, phenothiazine, phenyl-β-naphthylamine, and dodecylamine. A particularly effective method of preparing the basic salt involves mixing the acid with an excess of a basic alkaline earth metal neutralizing agent and at least one alcohol promoter, and carbonating the mixture at an elevated temperature, eg, 60 to 200°C. Overbased cleaners typically have a TBN (Total Base Number, ASTM D-2896) of 150 or greater such as 250-450.

Suitable calcium-containing detergents include, but are not limited to, neutral or overbased salts of such materials, such as calcium phenate, calcium phenate sulfur, in which each aromatic group has one or more aliphatic groups to bring about hydrocarbon solubilization calcium sulfonate, in which each sulfonic acid group is attached to an aromatic ring, which usually contains one or more aliphatic substituents to confer hydrocarbon solubility; calcium salicylate, in which the aromatic group is usually One or more aliphatic substituents substituted to bring about hydrocarbon solubility, hydrolyzed phosphosulfurized olefins with 10 to 2000 carbon atoms or hydrolyzed phosphosulfurized alcohols with 10 to 2000 carbon atoms and/or aliphatic groups Salts of phenolic compounds substituted by groups; calcium salts of aliphatic carboxylic acids and alicyclic carboxylic acids substituted by aliphatic groups; and salts of many other oil-soluble organic acids. Mixtures of neutral or overbased salts of two or more different alkali and/or alkaline earth metals may be used. Mixtures of two or more neutral and/or overbased salts of different acids (eg, one or more overbased calcium phenates and one or more overbased calcium sulfonates) may also be used.

As is well known, overbased metal cleaners are generally regarded as containing an overbased amount of inorganic base, which may be in microdispersion or colloidal suspension. The term "oil-soluble" thus applied to metal cleaners is intended to include metal cleaners in which the inorganic base need not be completely or truly oil-soluble in the strict sense of the term, since when such cleaners are mixed with the base , behave essentially the same as if they were fully and totally dissolved in the base oil.

The preparation of oil-soluble neutral and overbased metal cleaners and alkaline earth metal-containing cleaners is well known to those skilled in the art and is widely reported in the patent literature.见于例如美国专利2001108、2081075、2095538、2144078、2163622、2270183、2292205、235017、2399877、2416281、2451345、2451346、2485861、2501731、2501732、2585520、2671758、2616904、2616905、2616906、2616911、2616924、2616925、 2617049, 2695910, 3178638, 3367867, 3496105, 3629109, 3865737, 3907691, 4100085, 4129598, 4137184, 4184740, 4212752, 4617135, 4647387, 488055.

If desired, the metal cleaners useful in the present invention may be oil-soluble borated neutral and/or overbased alkali or alkaline earth metal cleaners. If desired, the metal cleaners useful in the present invention may be oil soluble borated neutral and/or overbased alkaline earth metal cleaner bases. Methods of making borided metal cleaners are described, for example, in US Pat.

Preferred calcium detergents for use in the present invention are overbased calcium sulfonates and calcium phenates and overbased sulfurized calcium phenates.

While any effective amount of calcium overbasing cleaner can be used to achieve the benefits of the present invention, typically an effective amount is 0.01-5.0% by mass of the product fluid. A preferred treat rate in the fluid will be 0.05-3.0% by mass, most preferably 0.1-1.0% by mass.

D. Succinimide-Based Friction Modifiers

An optional component of the present invention is a succinimide-based friction modifier of formula II:

Formula II

Wherein R ₂ and R ₃ may be the same or different and are C ₆ -C ₃₀ alkyl, and z=1-10.

The alkenyl succinimide starting material used to form the friction modifier of Formula II can be one of two types. The difference between the two classes of substances is the attachment of the alkyl side chain to the succinic acid moiety. In the first class, the alkyl group is attached through a primary carbon atom in the starting olefin, so the carbon atom adjacent to the succinic moiety is a secondary carbon atom. In the second class, the attachment is through a secondary carbon atom in the starting olefin, so these species have branched or isomerized side chains. Therefore the carbon atoms adjacent to the succinic acid moiety must be tertiary carbon atoms.

The first class of alkenyl succinic anhydrides having a linkage through a secondary carbon atom, as shown in Formula IV, is obtained by simply heating an alpha-olefin, a terminally unsaturated olefin, with maleic anhydride. Examples of such anhydrides would include n-decene Base succinic anhydride, tetradecenyl succinic anhydride, n-octadecenyl succinic anhydride, tetrapropenyl succinic anhydride, etc.

Formula IV

Wherein R is C ₃ to C ₂₇ alkyl.

A second class of alkenyl succinic anhydrides having linkage through a tertiary carbon atom is prepared from internal ethylenic unsaturation and maleic anhydride. Internal olefins are those that are not terminally unsaturated and therefore contain the following groups:

These internal olefins can be added to the reaction mixture as such, or can be generated in situ by contacting the alpha-olefin with the isomerization catalyst at elevated temperature. Methods for producing such materials are described in US Patent 3,382,172. Isomerized alkenyl substituted succinic anhydrides are compounds of formula V:

Type V

Wherein x and y are independently the integer whose sum is 1-30.

Preferred succinic anhydrides are obtained by isomerization of linear alpha-olefins using acidic catalysts followed by reaction with maleic anhydride. Preferred alpha-olefins are 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene or mixtures of these substances. The above products can be produced from internal olefins having the same carbon number, 8-20. Preferred substances of the present invention are made from 1-tetradecene (x+y=9), 1-hexadecene (x+y=11) and 1-octadecene (x+y=13) those obtained, or mixtures thereof.

Alkenyl succinic anhydrides are subsequently reacted with polyamines of formula V:

wherein z is an integer of 1-10, preferably 1-13.

The preferred succinimide friction modifiers of the present invention are produced by reacting isomerized alkenyl succinic anhydride with diethylenetriamine, triethylenetetramine, tetraethylenepentamine or mixtures thereof. The most preferred product is prepared using tetraethylenepentamine. Typically alkenyl succinic anhydrides are reacted with amines in a 2:1 molar ratio so that all primary amines are converted to succinimide. A slight excess of isomerized alkenyl succinic anhydride is sometimes used to ensure that all primary amines have reacted. The reaction product is a compound of formula II.

Both classes of succinimide friction modifiers can be used alone or in combination.

The disuccinimides of formula II can be worked up or further processed by various methods known in the art. These methods shall include, but are not limited to, boronation, maleic acid treatment, and treatment with mineral acids such as phosphoric acid, phosphorous acid, and sulfuric acid. These methods are described, for example, in US Patents 3254025, 3502677, 4686054, 4857214.

Another useful derivative of succinimides are those in which the alkenyl groups of formulas II, III and IV have been hydrogenated to form their saturated alkyl analogs. Saturation of the condensation products of olefins and maleic anhydride can be accomplished before or after the reaction with the amine. These saturated counterparts of the formulas II, III and IV can be worked up analogously as described above.

Although any effective amount of the compound of formula II and its derivatives can be used to obtain the beneficial effects of the present invention, generally these effective amounts are 0.01-10% by weight, preferably 0.05-7% by weight, most preferably 0.1-5% by weight of the final fluid. weight%.

Examples of methods for the preparation of compounds of formula II are given below.

Example FM-2-A : Into a 1 liter round bottom flask equipped with a mechanical stirrer, nitrogen purge, Dean-Stark trap and condenser was charged 352 grams (1.00 mol) of isoctadecenyl succinate Anhydride (ODSA available from Dixie Chemical Co.). A slow nitrogen purge was started, the stirrer was turned on and the mass was heated to 130°C. Immediately, 87 grams (0.46 mol) of commercial tetraethylenepentamine were slowly added to the heated isoctadecenyl succinic anhydride with stirring through a dropper. The temperature of the mixture was raised to 150°C and held at this temperature for 2 hours. 8 ml of water were collected in the Dean-Stark trap during this heating (-50% of theoretical yield). The flask was cooled to obtain the product and the product was weighed and analyzed. Yield: 427 grams. Nitrogen percentage: 7.2.

Example FM-2-B : The procedure of Example FM-2-A was repeated except that the following substances and amounts were used: n-octadecene succinic anhydride, 352 grams (1.0 mol) and tetramethylenepentamine, 87 grams (0.46 mol). 8ml of water was collected. Yield: 430 g. Nitrogen percentage: 7.1.

Example FM-2-C : The procedure of Example FM-2-A was repeated except that the following substances and amounts were used: isocadecenyl succinic anhydride, 458 grams (1.3 mol) and dimethylenetriamine, 61.5 grams (0.6 mol). 11 ml of water were collected. Yield: 505 g. Nitrogen percentage: 4.97.

Example FM-2-D : The procedure of Example FM-2-A was repeated except that the following materials and amounts were used: Isohexadecenyl succinic anhydride (ASA-100 obtained from Dixie Chemical Co.), 324 grams (1.0 mol), and tetramethylenepentamine, 87 grams (0.46 mol). 9ml of water was collected. Yield: 398 g. Nitrogen percentage: 8.1.

Example FM-2-E : The product of Example FM-2-A, 925 grams (0.1 mol), and 140 grams of naphtha base oil (available from ExxonMobile Chemical Co. at Necton-37 (commercially available under the trade mark of Dow Corning) and 1 gram of defoamer DC-200 sold by Dow Corning were placed in a 2-liter circle equipped with a heating mantle, upper stirrer, nitrogen purge, Dean-Stark trap, and condenser. in the bottom flask. The solution was heated to 80°C and 62 grams (1.0 mol) of boric acid was added. The mixture was heated to 140°C and maintained at this temperature for 3 hours. During this heating 3 ml of water were collected in the Dean-Stark trap. The product was cooled, filtered, weighed and analyzed. Yield: 1120 g. Nitrogen percentage: 6.1; Boron percentage: 0.9.

e. Organic phosphite

An optional component of the additive system of the present invention is an oil-soluble organic phosphite. Organic phosphites useful in the present invention are preferably mono- and dihydrocarbyl phosphites, the general formula of which is shown in Formula III:

Formula III

Wherein R ₄ is a hydrocarbon group, R ₅ is a hydrocarbon group or hydrogen; R ₄ or R ₅ preferably contains a sulfide group (CH ₂ -S-CH ₂ ). The term "hydrocarbyl" as used herein refers to a group which has a carbon atom directly attached to the remainder of the molecule and which, for the purposes of this invention, is predominantly hydrocarbon in character. Such groups include: (1) hydrocarbon groups; that is, aliphatic, alicyclic (such as cycloalkane or cycloalkene), aromatic groups, alkaryl groups, etc., and the rings are completed by other parts of the molecule Cyclic groups; (2) substituted hydrocarbyl groups; ie, hydrocarbyl groups containing non-hydrocarbon substituents which do not alter the essential properties of the hydrocarbyl group for the purposes of this invention. It will be clear to those skilled in the art which groups are suitable. Examples thereof include halogen, hydroxy, nitro, cyano, alkoxy, acyl and the like. (3) Hetero group; that is, a group which has mainly hydrocarbon properties in terms of the present invention but contains non-carbon atoms in its chain or ring. Those skilled in the art know that those atoms are suitable heteroatoms, such as nitrogen, oxygen and sulfur. In formula III, R ₄ or R ₅ is C ₁ to C ₂₀ alkyl, preferably C ₄ to C ₂₀ , more preferably C ₆ to C ₁₈ , most preferably C ₈ to C ₁₆ . These groups are well known to those skilled in the art, examples of which include methyl, ethyl, octyl, decyl, octadecyl, cyclohexyl, phenyl, and the like. _C4 or _C5 can also be varied independently. As stated, _R4 and _R5 can be alkyl, or aralkyl, which can be straight or branched, and aryl can be phenyl or substituted phenyl. The _R4 and _R5 groups can be saturated or unsaturated and can contain heteroatoms such as S, N or O. Preferred materials are dialkyl phosphites. The R ₄ and R ₅ groups are preferably C ₄ to C ₁₈ linear alkyl groups containing one sulfur atom. Most preferred are decyl, undecyl, 3-thioundecyl, pentadecyl, 3-thio-pentadecyl.

The phosphites of formula III can be used alone or in mixtures.

A preferred embodiment of the present invention is the use of mixed alkyl phosphites as described in US Pat. Nos. 5,185,090 and 5,242,612.

Although an effective amount of organophosphite can be used to obtain the benefits of the present invention, a typical effective amount is 0.01 to 5.0% by mass of the final fluid, with a preferred treat rate of 0.2% to 3.0%, most preferably 0.3% to 1.0% %.

Production examples of representative mixed organic phosphites are given below.

，可从美国EXXON Company公司得到)。经过分析发现最终产物含5.2％的磷，11.0％的硫。 Preparation of Example P-1-A-Alkyl Phosphite Mixture : Put 246g (1mol) of hydroxyethyl n-decyl in a 4-necked round bottom flask equipped with a reflux condenser, a stirring bar and a tube with nitrogen bubbles Alkyl sulfide, 122g (1mol) thiobisethanol (thiobisethanol), 194g (1mol) dibutyl phosphite. The flask was flushed with nitrogen, sealed and stirred. The contents were heated to 95°C under vacuum (-60 kPa). The reaction temperature was maintained at 95° C. until about 59 ml of butanol was collected in the cold trap as an overhead product. Heating was continued until the TAN (total acid number) of the reaction mixture reached approximately 110. This continuous heating takes about 3 hours, during which time no further butanol is evolved. With reaction mixture cooling, add 102g base oil (its trademark is Necton-37

, available from EXXON Company, USA). The final product was analyzed to contain 5.2% phosphorus and 11.0% sulfur.

Example P-1-B- Preparation of reaction products containing phosphorus and sulfur : 194 g (1 mol) of dihydrophosphorous acid was put into a four-necked round-bottomed flask equipped with a reflux condenser, a stirring bar and a tube for nitrogen bubbles butyl ester. The flask was flushed with nitrogen, sealed and stirred. Dibutyl hydrogen phosphite was heated to 150°C under vacuum (-90kPa), the temperature of the flask was kept at 150°C, and 190g (1mol) of hydroxyethyl n-octyl sulfide was added within about 1 hour. During the refeed, about 35 ml of butanol was recovered in the cold trap as overhead. Heating was continued for about 1 hour after the addition of the hydroxyethyl-n-octyl sulfide was complete. During this period, no new alcohol was evolved. The reaction mixture was cooled and analyzed for sulfur and phosphorus. The final product has a TAN of 115, contains 8.4% phosphorus, 9.1% sulfur.

Other additives known in the art may also be added to the CVT continuously variable transmission fluid of the present invention. These additives include other dispersants, antiwear agents, anticorrosion agents, auxiliary metal cleaners, extreme pressure additives, antioxidants, and the like. See, e.g., "Lubricant Additives," C.V. Smalheer and R. Kennedey Smith, 1967, pp. 1-11, and U.S. Patent 4,105,571

The amount of additive in a representative CTV fluid is as follows: additive Rough weight % Preferred wt% VI improver 1-12 1-4 anti-corrosion agent 0.01-3 0.02-1 Dispersant 0.10-10 2-5 Defoamer 0.001-5 0.001-0.5 Auxiliary Metal Cleaner 0.01-6 0.01-3 anti-wear agent 0.001-5 0.2-3 pour point depressants 0.01-2 0.01-1.5 seal expansion agent 0.1-8 0.5-5 Antioxidant 0.001-3 0.1-1.0 lubricating oil margin margin

The additive combination of the present invention can be mixed together with other desired lubricating oil additives to form concentrates. The active ingredient (a.i.) content of the concentrate is generally between 20 and 90% by weight of the concentrate, preferably between 25 and 85% by weight, most preferably between 35 and 75% by weight. The balance of the concentrate is the diluent, usually consisting of lubricating oil or solvent.

The following examples are used to specifically illustrate the present invention, and it should be understood that the present invention is not limited to the specific details described in the examples. All parts and percentages are by weight unless otherwise indicated.

Example

The polymeric features and examples of the present invention are presented for convenience only and additional embodiments can be constructed according to the present invention which also exhibit the benefits of the present invention. Those skilled in the art can recognize these implementations starting from the points set forth in the specification, and have consciously included them in the appended claims.

Example

To demonstrate the effectiveness of spirobisphosphites in increasing steel-steel friction, twelve experimental fluids were prepared and evaluated in standard tests for their ability to increase steel-steel friction. The test method is to use the Falex 1 type test equipment equipped with H60 test block and S10 test ring. Load the test ring with the test block by adding weight to the load pack. For each evaluation test cell, new parts were assembled and filled with 225 ml of lubricant. Once the test part and lubricant are in place, the temperature of the lubricant is raised to 80°C and the test ring is started to rotate at a fixed speed of 545 rpm. Add a 5 lb weight to the load pack and continue spinning for another 5 minutes, then add another 5 lb weight to the load pack (10 lbs total weight). Due to the multiplier effect of the load pack lever, this is equivalent to applying a weight of 100 lbs to the test block. After 10 minutes of sliding to brake the system, the measurements were made by exercising for 3 minutes at each of the 6 speeds. With the measurement of the lateral force generated by the coefficient of friction, the rotational speed decreases stepwise, measured at 545 (1.0), 273 (0.5), 136 (0.25), 68 (0.125), 55 (0.1) and 27 (0.05 ) The lateral force generated by the coefficient of friction of the fluid at rpm. Linear slide speeds (in m/s) are written in parentheses after each rotational speed. The coefficient of friction can be calculated from the measured lateral force. The table below shows the measured friction coefficients at 0.5 m/s (273 rpm) (slip speed that correlates well with the relative slip speed between the CVT belt and pulley in actual transmission operation). Data are the mean of two separate determinations.

For the purposes of these examples, 12 test lubricants were prepared using conventional Group II 100 neutral oils, the formulations of the test lubricant bases being as follows: components mass percent in oil Polyisobutenyl Succinimide Dispersant 3.0 Alkylated diphenylamine 0.25 Product of Example FM-2-C 1.0 Calcium Sulfonate (300TBN) 0.3 Polymethacrylate Viscosity Modifier 5.0

Then, each phosphorus source was added to the basic lubricant, and its concentration is shown in the table below, and the friction coefficient of the lubricant formed was determined by the above method.

The effect of phosphite

Four test lubricants were prepared using diisodecylpentaerythritol diphosphite (Westan 600), the product of Example P-1-B, zinc dialkyldithiophosphate (ZDDP) and dibutylhydrogenphosphite (DBHP). agent. The components were added to the test lubricant base so that the phosphorus concentration in the oil was all 300 ppm. The friction coefficient measurement results are shown in the table below.

Table 1 Phosphorus source ppm P coefficient of friction Westan 600 Cases of P-1-B Product ZDDPDBHP 300300300300 0.1250.1200.1200.116

The data in Table 1 show that the fluids containing the bicyclic phosphites of the present invention produced the highest coefficients of friction.

Effect of Concentration

Three test lubricants were prepared with different concentrations of diisodecylpentaerythritol diphosphite (Westan 600). The formulations of these lubricants and their measured coefficients of friction are listed in Table 2.

Table 2 Phosphorus source ppm P coefficient of friction Westan 600 100300500 0.1190.1250.126

The data in Table 2 illustrate that the coefficient of friction increases as the concentration of the spirobicyclic diphosphite of the present invention in the lubricant increases.

Effect of mixture

Six test lubricants were prepared using mixtures of the phosphites of the present invention and other sources of phosphorus as described above. The formulations and measured friction coefficients of these experimental lubricants are listed in Table 3.

table 3

When the spirobicyclic diphosphite of the present invention is mixed with other phosphites (such as the product of P-1-B or dibutyl hydrogen phosphite), the friction coefficient of the prepared lubricant is higher than that of other phosphites alone. High with phosphate, but not with zinc dithiophosphate. Thus, mixtures of the spirobicyclic diphosphites of the present invention with other phosphites are useful in increasing the steel-to-steel coefficient of friction of lubricants.

Claims (9)

1. be used for the lubricating composition of lubricated buncher, it comprises following component:

(1) lubricating oil of main amount; With

(2) the performance enhancer additives of significant quantity combination, it comprises:

(a) ashless dispersant of 0.5 to 7.0 quality %

(b) the spiral shell dicyclo diphosphites of 0.2 to 8.0 quality %, its structure is as follows:

Wherein R and R ₁Can independently change, and be C ₁-C ₂₀Aliphatic alkyl;

(c) calcium of 0.05 to 3.0 quality % cleaning lubricating oil additive

(d) Ren Xuan succinimide friction modifiers, its structure is:

R wherein ₂And R ₃Can independently change, and be C ₆-C ₃₀Alkyl, z=1-10 and

(e) Ren Xuan organophosphite, its structure is:

R wherein ₄Be C ₁-C ₂₀Alkyl, R ₅Be C ₁-C ₂₀Alkyl or hydrogen, its prerequisite are not contain molybdenum in the composition.

2. the composition of claim 1, wherein calcium cleaning lubricating oil additive is overbased sulfonate, phenates or sulfuration phenates.

3. the composition of claim 1, wherein ashless dispersant is a polyisobutenyl succinimide.

4. the composition of claim 1, the wherein R of spiral shell dicyclo diphosphites and R ₁Group is an isodecyl.

5. wherein there is component (e) in the composition of claim 1.

6. the composition of claim 1 wherein also contains the additive that is selected from viscosity modifier, oxidation inhibitor, sealing swelling agent, anticorrosive agent, defoamer, antiwear agents, assistant metal sanitising agent and pour point reducer.

7. be used for the lubricating composition of lubricated buncher, it comprises following component:

(1) lubricating oil of main amount; With

(2) the performance enhancer additives of significant quantity combination, it comprises:

(a) ashless dispersant of 0.5 to 7.0 quality %

(b) the spiral shell dicyclo diphosphites of 0.2 to 8.0 quality %, its structure is as follows:

Wherein R and R ₁Can independently change, and be C ₁-C ₂₀Aliphatic alkyl;

(c) calcium of 0.05 to 3.0 quality % cleaning lubricating oil additive

(d) Ren Xuan succinimide friction modifiers, its structure is:

R wherein ₂And R ₃Can independently change, and be C ₆-C ₃₀Alkyl, z=1-10,

With

(e) Ren Xuan organophosphite, its structure is:

R wherein ₄And R ₅Group is the straight chained alkyl that contains a sulphur atom that 4 to 18 carbon atoms are arranged, and its prerequisite is not contain molybdenum in the composition.

8. the composition of claim 7 wherein also contains the additive that is selected from viscosity modifier, oxidation inhibitor, sealing swelling agent, anticorrosive agent, defoamer, antiwear agents, assistant metal sanitising agent and pour point reducer.

9. the method for lubricated stepless speed change device comprises that each composition is operated said apparatus among the use claim 1-8.